infer vs thresh out

infer

verb
  • To introduce (something) as a reasoned conclusion; to conclude by reasoning or deduction, as from premises or evidence. 

  • To lead to (something) as a consequence; to imply. 

thresh out

verb
  • To extract or remove by threshing. 

  • To thrash out. 

How often have the words infer and thresh out occurred in a corpus of books? (source: Google Ngram Viewer )